The subject matter herein relates generally to battery distribution units (BDUs) for battery systems.
Batteries, such as those for electric vehicles or hybrid vehicles, typically include a plurality of cells grouped together as a battery pack. The battery pack includes a battery distribution unit that manages the power capacity and functionality of the battery pack. The battery distribution units are typically mounted inside a casing of the battery pack. The BDU includes many electric devices such as at least one power relay, at least one pre-charge relay, at least one pre-charge resistor, at least one Y-capacitor, at least one fuse, a current sensor, and other electric devices.
Conventional BDUs use bolt/nut connections, increasing the number of components within the BDU housing and increasing the assembly time. The size of the BDU is relatively large to accommodate the connections. The large number of parts increases the cost of the BDU. Other BDU designs utilize customized busbars, which are typically stamped and formed busbars having the busbar arranged horizontally with stamped blades formed 90° to extend vertically to mate with the devices. Bolt/nut connections may be utilized with such busbars. Other systems use box terminals that fit onto the blades. Conventional 12V fuse-relay boxes having customized busbars typically arrange the busbars on multiple (e.g. four) different layers, which increases the overall cost and package size of the 12V fuse relay box. The systems are complex and have many components. Such systems have no design flexibility to adapt to different orientations, available spaces and shapes. Such systems are also difficult to integrate with other connectors or devices. Additionally, for the customized busbar, the blade position tolerance is very difficulty to control. Sometimes, it may be difficult to accommodate for the blade orientation of the devices. Cost is a major disadvantage of such systems.
There is a need for a robust BDU, which is flexible in design and small in size for locating within the battery system. There is a need for a BDU capable of accommodating device location such as relays, fuses, resistor and the like.